Using act doesn't update state? - reactjs

Question

I have a custom hook like so:
import { useState } from 'react';
export default function useOpenClose(initial = false) {
const [isOpen, setOpen] = useState(initial);
const open = () => { setOpen(true); }
const close = () => { setOpen(false); }
return [isOpen, { open, close } ];
}
and as for my tests I have something like this:
import { renderHook, act } from '#testing-library/react-hooks';
import useOpenClose from './useOpenClose';
describe('useOpenClose', () => {
const { result: { current } } = renderHook(() => useOpenClose());
const [isOpen, { open, close }] = current;
test('Should have an open function', () => {
expect(open).toBeInstanceOf(Function)
});
test('Should have an open function', () => {
expect(close).toBeInstanceOf(Function)
});
test('Should have initial value of false', () => {
expect(isOpen).toBe(false);
});
test('Should update value to true', () => {
act(() => open());
console.log(isOpen)
})
});
Where the test "'Should update value to true'", when I log isOpen, it stays false. I'm not exactly sure why it's not updating unless act isn't doing what it's doing?

Answer 1

From the doc Updates:
NOTE: There's a gotcha with updates. renderHook mutates the value of current when updates happen so you cannot destructure its values as the assignment will make a copy locking into the value at that time.
E.g.
useOpenClose.ts:
import { useState } from 'react';
export default function useOpenClose(initial = false) {
const [isOpen, setOpen] = useState(initial);
const open = () => {
setOpen(true);
};
const close = () => {
setOpen(false);
};
return [isOpen, { open, close }] as const;
}
useOpenClose.test.ts:
import { act, renderHook } from '#testing-library/react-hooks';
import useOpenClose from './useOpenClose';
describe('useOpenClose', () => {
test('should pass', () => {
const { result } = renderHook(() => useOpenClose());
// Don't destructure `result`.
expect(result.current[1].open).toBeInstanceOf(Function);
expect(result.current[1].close).toBeInstanceOf(Function);
expect(result.current[0]).toBe(false);
act(() => result.current[1].open());
console.log(result.current[0]);
});
});
Test result:
PASS examples/57315042/useOpenClose.test.ts (13.635 s)
useOpenClose
✓ should pass (45 ms)
console.log
true
at Object.<anonymous> (examples/57315042/useOpenClose.test.ts:12:13)
-----------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
-----------------|---------|----------|---------|---------|-------------------
All files | 87.5 | 100 | 66.67 | 87.5 |
useOpenClose.ts | 87.5 | 100 | 66.67 | 87.5 | 10
-----------------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 15.588 s